I have been following your story about this new BAT preamp in your other threads, as well, with interest. Here's what I know for sure. BAT preamps, tube or solid state, don't make noise. I have nothing to do with the company and don't currently own any BAT equipment but I know your problem is not normal. I know people that have used BAT amps and preamps with ultra efficient speakers, like horn designs, and they are dead quiet even under the most demanding applications.
In my opinion, this is the safest and easiest way to get to the bottom of what your problem is. 1. Call BAT. I'm pretty sure that you have some tube issues. Given your explanations in the other threads, I'm not 100% convinced, though. I would explain the problem to BAT and see what they say. You have nothing to lose and BAT is very concerned about quality issues. 2. If you do need tubes, try to go about it with 0 risk. I recommend The Cable Company. Yes, they are known for cables, but they sell a huge amount of tubes, as well. They are also known for their lending program. They lend me all kinds of stuff other than cables to try before I make a purchase. I am fairly certain that they will lend tubes as well, but you will need to ask them. 3. I know in the other thread, I said you made a good purchase. I stand by it. You probably just need a new set of tubes. Don't make a nightmare out of this for yourself. Get the preamp working, listen to some music and don't 2nd guess every little thing. You'll see what I mean once you get the preamp working.